Emplate (Marius St. Croix)
Perhaps Generation X's greatest and most feared foe, Emplate is also the brother of Monet. As children, Marius was constantly put down by Monet, causing his anger and frustration with his younger sister to grow over the years. When Emplate came to Monet, asking if she wanted to help him take over the world, Monet once again ran her mouth. Finally fed up with her attitude, Emplate magically transformed Monet into the creature known as Penance! For years, Monet was trapped in the diamond-hard, razor-sharp body of Penance. Being a "genetic vampire", Marius constantly needed to sup on other mutants' genetic marrow. And being a prisoner of Emplate's, "Penance" served as his "meal" for what is believed to be a few years, until Gateway freed her from Marius' clutches. Needless to say, Emplate and Monet have some serious unresolved issues with each other...

Emma Frost
In one of Gen X's earliest missions, Monet was going to attack the evil Emplate head-on, but she was stopped psionically when Emma grabbed a hold of her senses. Monet was furious at Emma for entering her mind. The same day, Monet explained to Emma that while she did not like Emma's lack of clothes and disregard to other people's privacy, it would take awhile for her to say with assurance that she did not like Emma. Later in the series, Emma was fed up with Monet's secrets, and told Monet that she could cooperate and tell her the truth, or it would be forced from her. Monet fought back, but after doing so, Monet told Emma she would reveal what she could, though, to my knowledge, this never happened. (Note: All this happened while the twins were still posing as Monet. It is not known what the true Monet's relationship with Emma is like.)

Jubilee (Jubilation Lee)
Jubilee and Monet are complete opposites -- Jubilee an immature California mall-rat, and Monet an intellectual, high-society girl. However, it gets more complicated. Early in the series, Monet was actually the twins. As Monet, the twins constantly bumped heads with Jubilee. But the TRUE Monet, inside Penance's body, was actually friends with Jubilee! She was the closest thing to a friend "Penance" had. But when the twins finally traded places with their sister, and the true Monet returned to her rightful body, the rivalry between Jubilee and Monet remained. In fact, it got so heated, the two duked it out in a one-on-one fight! As they fought, Monet explained to Jubilee that hating Jubilee comes natural to her, and during her time as Penance, she felt Jubilee treated her like a pet. Jubilee assures Monet that next time she messes with her, she's really going to get it.

Synch (Everett Thomas)
Up until around Gen X #30, Synch and M never really talked to each other. But when they were being hunted by Prime Sentinels, Monet (the twins) unexpectedly kissed Everett! Immediately after, the Prime Sentinels found them, and buried them under a pile of rubble. When Synch freed himself, he looked for Monet, only to find the twins. Several issues later, Everett once again finds himself stumbling upon another St. Croix secret -- the mystery of Penance! He made the twins reveal to the rest of the team that Penance was in fact Monet. With the real Monet in Monet's body, she had set her sights on Everett! During a trip to Boston, Monet was going to kiss Everett, though the moment was interrupted by a member of Gene Nation. In #67 (chronologically placed between #62 and #63), Monet and Everett finally got together romantically, although Synch was killed shortly after their relationship started. After Ev's death, Monet has become very emotionally distraught and unfocused. Even though all the others have moved on with their lives (including Jubilee), Monet is still grieving his death.

Nicole and Claudette St. Croix
When Monet was turned into Penance by Emplate, Nicole and Claudette didn't know what happened. All they knew was that their sister was missing, and Emplate and a strange girl (Penance) was there. The twins banished Emplate into another dimension, but he also took Penance with him. Confused, the twins joined bodies to replicate their older sister Monet. It appears that Monet was their father's favorite daughter, and what held the family together. It wouldn't be a few years later that Nicole and Claudette would find out the truth about what happened to their sister. When the twins learned this, they felt guilty, and traded bodies with the real Monet in Penance's body, leaving the two girls in Penance's form, and Monet in her true body. The twins, however, have since managed to be free from the Penance body, leaving Penance as its own being. It is common fact that Nicole and Claudette may very well be one of the few people Monet truly cares about. In fact, Nicole has mentioned that Monet was the only one in their family who treated them (the twins) kindly.

Penance
As explained above, Monet was actually Penance for quite sometime, at the hands of her evil brother, Emplate. Monet was forced to live inside the diamond-hard, razor-sharp, mute body of Penance for a few years, until she was rescued by Gateway and brought to Gen X. It was with Generation X that Monet's twin sisters found out Monet was really Penance, and they freed Monet from the "prison", only for the young twins to be trapped inside. Recently, the twins were set free from Penance after an explosion which caused them to seperate. But, somehow, the Penance body survived, and with a mind of its own. As of right now, there is no direct relationship between Monet and the current Penance (whoever it is). However, after Penance's disappearance in the six months between #62 and #63, it doesn't look like Monet will be able to develop any kind of relationship with the "new" Penance.

Gateway
Gateway has an unrevealed connection with the St. Croix family. First of all, it was he who freed "Penance" (Monet) from Emplate and brought her to Generation X. It has since been learned that it was his own penance for his part in the deaths of the Hellions. However, "Monet" (the twins) seemed to have known Gateway from the past. He was referred by (the faux) Monet as "Mentor", and, during his time with Gen X, seemed to be Monet's private teacher. Monet confided with Gateway, and is known to have meditated with the mysterious old man. In fact, Gateway seems to be one of the very few people Monet truly respects. Gateway also seems to know about Emplate, since it was he who warned Monet about her brother's first attack (see Gen X #1). However, we will have to wait until Gateway returns to the Academy to learn his true connection with Monet, the twins, and Marius...